The invention relates to an antenna system, in particular a high-power microwave antenna with a pulse generating source for generating a pulse to be radiated toward a target.
For the realization of indirectly conveyed HPM (high-power microwave) active systems, antennas or antenna systems requiring little structural space must be provided to meet the carrier system requirements. In addition, these should also meet the HPM source requirements with respect to voltage-sustaining capacity, surface quality, antenna gain, directional efficiency, etc.
U.S. Pat. No. 5,671,133 discloses a HPM source, for example, for a HPM active system.
A HPM active system that is conveyed is described in U.S. Pat. No. 5,192,827. For the non-lethal destruction of a target, meaning destruction of only the electronic components of the target, this HPM active system is provided with a projectile as carrier system. A TEM (transverse electromagnetic) horn antenna, an arrangement of dipoles, or a helical antenna (wire) with angular accuracy, is proposed for the microwave antenna. The antenna gain and directional efficiency are very low and non-homogeneous, particularly for wire-type antennas. The field intensity that can be radiated is determined by the environmental conditions of the HPM active system. The maximum field intensity that can be radiated with horn antennas is restricted by the horn antenna aperture size that is subject to the geometric edge parameters of the carrier system.
The configuration of a horn antenna used as a ground station antenna for satellite radio is described in European published Application Patent Application No. EP 0 128 970 A1. Another type of horn antenna is known from U.S. Pat. No. 5,568,160 and a cylindrical hybrid horn antenna is described in U.S. Pat. No. 4,783,665. The principle of a multi-horn antenna follows from the U.S. Pat. Nos. 5,113,197 as well as 4,758,842.
The aforementioned microwave antennas are not suitable for use especially in conveyable HPM active systems because the structural space for installing these types of antennas does not exist in the carrier system.
Thus, it is the object of the invention to provide an antenna that requires little structural space and additionally permits the radiation of short HPM pulses.
This object generally is achieved according to the present invention by an antenna system, in particular a high-power microwave antenna system, comprising a pulse-generating source for generating a pulse to be radiated by the antenna toward a target; an antenna formed by a conductive inner surface of an antenna airbag that is electrically connected to the pulse-generating source; and a gas generator for filling the antennas airbag with a gas to inflate the airbag and render it operative for radiating the pulse from the source.
The invention is based on the idea of creating an antenna by using an airbag that inflates near the target, so that HPM pulses, created by an HPM source, can subsequently be radiated onto the target. By integrating the antenna into a conveying carrier system, it is possible to use an airbag that already exists in the carrier system or to install an additional airbag in the carrier system. An existing airbag of this type is described in German published Patent Application No. 34 32 614 A1, which is designed to unfold the vanes of a projectile (carrier system) for the operating position.
Further advantageous embodiments are disclosed and described.
Thus, the airbag (antenna airbag) can be a horn antenna, a reflector or a Cassegrain-type reflector antenna and can simulate these either in part or completely.
The Cassegrain-type reflector antenna in this case preferably can comprise a horn antenna as feeding system and a curved reflecting surface on the rear antenna airbag or a combination antenna airbag and parachute. For a modification, a horn-shaped airbag is integrated into the Cassegrain-type reflector antenna, which in turn functions as the feeding system. This measure increases the antenna aperture, thus making it possible to increase the maximum achievable field intensity at the feeding location as well as increase the antenna gain or the directional characteristic.
The antenna airbag is filled either completely or partially with electronegative gas to further increase the maximum power that can be radiated and thus the maximum achievable field intensity.
In order to improve the radiation property of the antenna, the transmitting or antenna aperture can be improved or enlarged by individually designing the antenna airbag. Thus, the reflector curvature can be adjusted ideally by tailoring the airbag.
This type of solution offers a space-saving antenna, which does not influence the requirements that must be met by the carrier system (artillery shell, rocket, drone, projectile, etc.) with respect to volume, weight, acceleration stability, flow characteristics, etc., particularly if installed in a carrier system to be conveyed, but which nevertheless ensures a secure radiation of short HPM pulses.
The invention is explained in further detail with exemplary embodiments and drawings.